This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project compares trajectories of cognitive and brain aging in Homo sapiens with the pattern of aging in two closely related primate species, Pan troglodytes and Macaca mulatta. One key element of the project is the construct validity study being carried out at Georgia Institute of Technology under the direction of Dr. Anderson Smith. Approximately 200 normal human subjects have been tested in this study to examine the validity of widely used monkey tasks in assessing performance on specific domains of human cognitive function. This portion of the study has demonstrated that there are indeed age-related changes in humans that negatively affect performance of those tasks developed for the non human primate (NHP). Analyses are now underway to determine whether declines in performance of these tasks correlate with declines in tasks in common use in the studies of human cognitive aging. The NHP studies involve 36 chimpanzees and 24 rhesus monkeys. Each NHP undergoes a behavioral test battery designed to assess specific aspects of cognitive functioning that can be linked to brain regions such as the dorsolateral prefrontal cortex (dlPFC) or the hippocampal formation. In addition, we have recently added a series of tasks for the chimpanzee that have been used in comparative studies of childhood and development in humans and chimpanzees. During the past project year, we have also refined and developed the set of tasks that are to be used with healthy humans, as well as in humans with Mild Cognitive Impairment of the amnestic variety and in patients with Alzheimer's disease. These behavioral studies, as well as complementary in vivo neuroimaging studies, will shed light upon the differences in cognitive and aging processes that foster the human-specific pattern of aging and disease and will therefore inform strategies of therapeutic intervention in the human clinic.